Yes, your system should be perfectly fine for the standard Ubuntu. ...But, the beauty of all the Ubuntu variants is that you can try them all without installing. You can put each on a CD/DVD or USB stick and try them out first.

I think you will find both Kubuntu and Ubuntu too slow on your hardware but feel free to give them a try.

Xubuntu is a lighter desktop which should be reasonably fast on your machine. This would be my personal choice.